1. Field of the Invention
The invention is related to vertically adjustable stunners for electrically stunning poultry after the killing operation.
2. Description of the Prior Art
In modern poultry processing plants, the poultry is transported to various processing operations along a continuous conveyor in the form of a track. The poultry is suspended in shackles, by its feet, upside down. The poultry is transported along the track, and passed through a killing station wherein the jugular veins of the poultry is cut. The heart of each bird beat after the bird passes through the killing station, forcing blood from the bird through the now cut jugular vein.
Electric shocks have been used to immobilize the birds both before and after killing, as disclosed in U.S. Pat. Nos. 3,828,397, (pre-stunning), 2,335,993, and 3,474,490, (post stunning), and 2,306,773, (pre-stunning and post stunning). As disclosed in U.S. Pat. No. 2,335,993, a cross bar arrangement maybe used for shocking the birds. The cross bar arrangement is vertically adjustable and mounted to downwardly depending bars supported by the conveying track. Stunning devices have to be adjusted vertically to account for birds of different sizes, to insure for adequate electrical contact. Proposed vertical adjustment means disclosed in the above-identified patents include manually operated screw threaded jacking means, manually adjustable gear contacting racks, and manual positioning and frictional holding of the stunner.